1. Technical Field
This disclosure relates to a communication terminal, a method, a program and a recording medium and more particularly to communication control technology for a facsimile that communicates image information in electronic mail data format via a network through which plural communication terminals intercommunicate with an Internet protocol.
2. Description of the Related Art
In recent years and continuing, there is a growing demand for multifunctional apparatuses, being combinations of, for example, a facsimile, a copier, and/or a printer, which enable effective use of a network. Furthermore, in addition to electronic documents which are becoming more commonly used in the office, a facsimile communication system, which uses facsimiles for transmitting image information by attaching the image information to electronic mail in compliance with a MIME format, is becoming widely used for communicating with, for example, clients outside the office.
As for ITU-T recommendations regarding communication standards for facsimile transmission via the Internet, there is, for example, Recommendation T.38 (Real-time type) which is a facsimile transmission procedure for transmitting image information by intercommunication of communication terminals directly connected to the Internet, and Recommendation T.37 (Store and Forward type) which is a facsimile transmission procedure for transmitting image information by first storing the image information in a mail server device and intercommunicating the mail server devices with, for example, SMTP (Simple Mail Transfer Protocol).
As for other recommendations providing facsimile communications functions complying with the ITU-T Recommendation T.37, there is, for example, a “Simple Mode” which has neither a function of confirming the functionality of a receiving destination communication terminal when transmitting a document nor a function of sending a mail confirming receipt of the document via the Internet, and a “Full Mode” which has both the function of confirming the functionality of a receiving destination communication terminal when transmitting a document and the function of sending the mail confirming receipt of the document via the Internet.
Furthermore, other technical standards and specifications regarding, for example, communication protocols (e.g. TCP/IP, SMTP, POP), data formats and data structures of electronic mail are provided in the RFC (Request For Comments) issued by IETF (Internet Engineering Task Force).
The Recommendation T.37 and the RFC 2305 (Simple Mode) or RFC 2532 (Full Mode) are both applied with a common electronic mail data format, to thereby allow a communication terminal complying with Recommendation T.37 to intercommunicate information with a communication terminal or workstation device that has installed a software complying with RFC 2305 or RFC 2532.
However, with the Recommendation T.37 and the RFC 2305, image information that is to be transmitted is bound to fixed conditions (number of horizontal pixels: 1728 pixels; resolution: 200×100 dpi or 200×200 dpi; compression: MH); and is required to be attached to an electronic mail message and use a designated mail address for transmission and receipt of the image information. This prevents image information with higher quality from being transmitted and received.
In Japanese Laid-Open Patent Application No.2000-347954, a sender communication terminal compresses readout image data according to a fixed parameter, attaches the image information to an electronic mail message, and transmits the image information along with information indicating a self-controlling method, and identification information for requesting information of the function of a receiver communication terminal. In a case where the receiver communication terminal has installed a general type of electronic mail software, the attached image information is output in a form complying with the predetermined conditions.
In a case where the receiver communication terminal has installed a control method which is the same as that of the sender communication terminal, the image information is not required to be output by attachment to the electronic mail in compliance with predetermined conditions. Instead, the receiver communication terminal responds to the sender communication terminal by sending a message describing information on its own control method and its own capabilities.
The sender communication terminal generates image information including data regarding size, resolution, and/or compression of the image in accordance with the capabilities of the receiver communication terminal, attaches the image information to an electronic mail message, and re-transmits the mail, thereby enabling transmission of image information with higher quality.
Accordingly, the example proposed in Japanese Laid-Open Patent Application No.2000-347954 is able to have affinity with a receiver communication terminal that has installed a general type of electronic mail software, and also transmit images in accordance with the capabilities (image information conditions) of a receiver communication terminal when the receiver communication terminal has capabilities the same as those of the sender communication terminal.
In Japanese Laid-Open Patent Application No.2001-313778, a store and forward type network facsimile (technology) is able to transmit its capability information to a receiver communication terminal by writing capability information into a preamble part and an epilogue part of an electronic mail message defined in a multi-part form of MIME without affecting the main text of the electronic mail. Furthermore, when the message of the electronic mail is received, the sender communication terminal stores capability information relative to the mail address of the receiver communication terminal so that image information, next time, can be transmitted in accordance with the receiver communication terminal. Accordingly, image information can be transmitted with higher quality.
Accordingly, the example proposed in Japanese Laid-Open Patent Application No.2001-313778 is a store and forward type technology which is able to transmit capability information without affecting the main text of the electronic mail message, and utilize the capability information.
However, the example proposed in Japanese Laid-Open Patent Application No.2000-347954 requires an increased workload (process load) for generating compressed data, and burdens the mail server since the example employs a process of generating image information including data regarding size, resolution, and/or compression of the image in accordance with the capabilities of the receiver communication terminal, attaching the image information to an electronic mail message, and re-transmitting the electronic mail when the receiver communication terminal has capabilities the same as those of the sender communication terminal, while still achieving affinity with a receiver communication terminal that has installed a general type of electronic mail software. In addition, the re-transmission of the electronic mail increases undesired communications traffic, burdens the network, and adversely affects other communications.
Furthermore, since the example proposed in Japanese Laid-Open Patent Application No.2001-313778 conducts an update on the conditions (capability) for image information transmission by employing a full mode provided with functions including capability confirmation and acknowledgement of receipt, the example has a problem where broadcast transmission, against the will of the user, cannot be conducted due to the update of capability of the receiver communication terminal. In addition, the example has a problem of requiring that all image information files attached to the electronic mail must be the same for conducting broadcast transmission to a plurality of receiver communication terminals.